Self-Driving Car Engineer Nanodegree

Deep Learning

Project: Build a Traffic Sign Recognition Classifier

In this notebook, a template is provided for you to implement your functionality in stages, which is required to successfully complete this project. If additional code is required that cannot be included in the notebook, be sure that the Python code is successfully imported and included in your submission if necessary.

Note: Once you have completed all of the code implementations, you need to finalize your work by exporting the iPython Notebook as an HTML document. Before exporting the notebook to html, all of the code cells need to have been run so that reviewers can see the final implementation and output. You can then export the notebook by using the menu above and navigating to \n", "File -> Download as -> HTML (.html). Include the finished document along with this notebook as your submission.

In addition to implementing code, there is a writeup to complete. The writeup should be completed in a separate file, which can be either a markdown file or a pdf document. There is a write up template that can be used to guide the writing process. Completing the code template and writeup template will cover all of the rubric points for this project.

The rubric contains "Stand Out Suggestions" for enhancing the project beyond the minimum requirements. The stand out suggestions are optional. If you decide to pursue the "stand out suggestions", you can include the code in this Ipython notebook and also discuss the results in the writeup file.

Note: Code and Markdown cells can be executed using the Shift + Enter keyboard shortcut. In addition, Markdown cells can be edited by typically double-clicking the cell to enter edit mode.


Step 0: Load The Data

In [1]:
import pickle
import numpy as np
import matplotlib.pyplot as plt
import cv2
import pandas as pd
from sklearn.utils import shuffle
import tensorflow as tf
from tensorflow.contrib.layers import flatten
import os
import matplotlib.image as mpimg
from PIL import Image

# Visualizations will be shown in the notebook.
%matplotlib inline
In [2]:
# Load pickled data
# TODO: Fill this in based on where you saved the training and testing data

training_file = '../../../../data/train.p'
validation_file= '../../../../data/valid.p'
testing_file = '../../../../data/test.p'

with open(training_file, mode='rb') as f:
    train = pickle.load(f)
with open(validation_file, mode='rb') as f:
    valid = pickle.load(f)
with open(testing_file, mode='rb') as f:
    test = pickle.load(f)
    
X_train, y_train = train['features'], train['labels']
X_valid, y_valid = valid['features'], valid['labels']
X_test, y_test = test['features'], test['labels']
In [3]:
print('X_train.shape is ',X_train.shape)
print('y_train.shape is ',y_train.shape)
print('X_valid.shape is ',X_valid.shape)
print('y_valid.shape is ',y_valid.shape)
print('X_test.shape is ',X_test.shape)
print('y_test.shape is ',y_test.shape)
X_train.shape is  (34799, 32, 32, 3)
y_train.shape is  (34799,)
X_valid.shape is  (4410, 32, 32, 3)
y_valid.shape is  (4410,)
X_test.shape is  (12630, 32, 32, 3)
y_test.shape is  (12630,)

Step 1: Dataset Summary & Exploration

The pickled data is a dictionary with 4 key/value pairs:

  • 'features' is a 4D array containing raw pixel data of the traffic sign images, (num examples, width, height, channels).
  • 'labels' is a 1D array containing the label/class id of the traffic sign. The file signnames.csv contains id -> name mappings for each id.
  • 'sizes' is a list containing tuples, (width, height) representing the original width and height the image.
  • 'coords' is a list containing tuples, (x1, y1, x2, y2) representing coordinates of a bounding box around the sign in the image. THESE COORDINATES ASSUME THE ORIGINAL IMAGE. THE PICKLED DATA CONTAINS RESIZED VERSIONS (32 by 32) OF THESE IMAGES

Complete the basic data summary below. Use python, numpy and/or pandas methods to calculate the data summary rather than hard coding the results. For example, the pandas shape method might be useful for calculating some of the summary results.

Provide a Basic Summary of the Data Set Using Python, Numpy and/or Pandas

In [4]:
### Replace each question mark with the appropriate value. 
### Use python, pandas or numpy methods rather than hard coding the results

# TODO: Number of training examples
n_train = X_train.shape[0]

# TODO: Number of validation examples
n_validation = X_valid.shape[0]

# TODO: Number of testing examples.
n_test = X_test.shape[0]

# TODO: What's the shape of an traffic sign image?
image_shape = (X_train.shape[1],X_train.shape[2])

# TODO: How many unique classes/labels there are in the dataset.
n_classes = len(np.unique(y_train))


print("Number of training examples =", n_train)
print("Number of validation examples =", n_validation)
print("Number of testing examples =", n_test)
print("Image data shape =", image_shape)
print("Number of classes =", n_classes)
Number of training examples = 34799
Number of validation examples = 4410
Number of testing examples = 12630
Image data shape = (32, 32)
Number of classes = 43

Include an exploratory visualization of the dataset

Visualize the German Traffic Signs Dataset using the pickled file(s). This is open ended, suggestions include: plotting traffic sign images, plotting the count of each sign, etc.

The Matplotlib examples and gallery pages are a great resource for doing visualizations in Python.

NOTE: It's recommended you start with something simple first. If you wish to do more, come back to it after you've completed the rest of the sections. It can be interesting to look at the distribution of classes in the training, validation and test set. Is the distribution the same? Are there more examples of some classes than others?

Data exploration visualization

In [6]:
# Plotting thresholded images
ix2=np.random.randint(0,n_train,size=2)
title1='label '+str(y_train[ix2[0]])
title2='label '+str(y_train[ix2[1]])
f, (ax1, ax2) = plt.subplots(1, 2)
ax1.set_title(title1)
ax1.imshow(X_train[ix2[0]])
ax2.set_title(title2)
ax2.imshow(X_train[ix2[1]])
Out[6]:
<matplotlib.image.AxesImage at 0x7f4b0ce78d30>
In [7]:
def plot_img(img):
    f, ax = plt.subplots()
    ax.imshow(img)

def plot_img_gray(img,gray):
    title1='color'
    title2='gray'
    f, (ax1, ax2) = plt.subplots(1, 2)
    ax1.set_title(title1)
    ax1.imshow(img)
    ax2.set_title(title2)
    ax2.imshow(gray,cmap='gray')

def plot_img_gray_scld(img,gray,scld):
    title1='color'
    title2='gray'
    title3='scaled'
    f, (ax1, ax2, ax3) = plt.subplots(1, 3)
    ax1.set_title(title1)
    ax1.imshow(img)
    ax2.set_title(title2)
    ax2.imshow(gray,cmap='gray')
    ax3.set_title(title3)
    ax3.imshow(scld,cmap='gray')
    plt.savefig('ref/img_gray_scld.png')
In [131]:
# sample image
img=X_train[2586]
gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)
scld = (gray - 128.0)/ 128.0
plot_img_gray_scld(img,gray,scld)

Class frequency

In [57]:
df=pd.read_csv('signnames.csv')

df['Count']=pd.value_counts(y_train)

#plt.bar(df.ClassId,df.Count,orientation='horizontal')
f, ax = plt.subplots(1, 1,figsize=(20,15))
ax.set_title('number of instances')
ax.barh(df.ClassId,df.Count)
_=plt.yticks(df.ClassId, df.SignName)
plt.savefig('ref/sample_count.png',bbox_inches='tight')
In [58]:
df
Out[58]:
ClassId SignName Count
0 0 Speed limit (20km/h) 180
1 1 Speed limit (30km/h) 1980
2 2 Speed limit (50km/h) 2010
3 3 Speed limit (60km/h) 1260
4 4 Speed limit (70km/h) 1770
5 5 Speed limit (80km/h) 1650
6 6 End of speed limit (80km/h) 360
7 7 Speed limit (100km/h) 1290
8 8 Speed limit (120km/h) 1260
9 9 No passing 1320
10 10 No passing for vehicles over 3.5 metric tons 1800
11 11 Right-of-way at the next intersection 1170
12 12 Priority road 1890
13 13 Yield 1920
14 14 Stop 690
15 15 No vehicles 540
16 16 Vehicles over 3.5 metric tons prohibited 360
17 17 No entry 990
18 18 General caution 1080
19 19 Dangerous curve to the left 180
20 20 Dangerous curve to the right 300
21 21 Double curve 270
22 22 Bumpy road 330
23 23 Slippery road 450
24 24 Road narrows on the right 240
25 25 Road work 1350
26 26 Traffic signals 540
27 27 Pedestrians 210
28 28 Children crossing 480
29 29 Bicycles crossing 240
30 30 Beware of ice/snow 390
31 31 Wild animals crossing 690
32 32 End of all speed and passing limits 210
33 33 Turn right ahead 599
34 34 Turn left ahead 360
35 35 Ahead only 1080
36 36 Go straight or right 330
37 37 Go straight or left 180
38 38 Keep right 1860
39 39 Keep left 270
40 40 Roundabout mandatory 300
41 41 End of no passing 210
42 42 End of no passing by vehicles over 3.5 metric ... 210
In [59]:
df.to_html
Out[59]:
<bound method DataFrame.to_html of     ClassId                                           SignName  Count
0         0                               Speed limit (20km/h)    180
1         1                               Speed limit (30km/h)   1980
2         2                               Speed limit (50km/h)   2010
3         3                               Speed limit (60km/h)   1260
4         4                               Speed limit (70km/h)   1770
5         5                               Speed limit (80km/h)   1650
6         6                        End of speed limit (80km/h)    360
7         7                              Speed limit (100km/h)   1290
8         8                              Speed limit (120km/h)   1260
9         9                                         No passing   1320
10       10       No passing for vehicles over 3.5 metric tons   1800
11       11              Right-of-way at the next intersection   1170
12       12                                      Priority road   1890
13       13                                              Yield   1920
14       14                                               Stop    690
15       15                                        No vehicles    540
16       16           Vehicles over 3.5 metric tons prohibited    360
17       17                                           No entry    990
18       18                                    General caution   1080
19       19                        Dangerous curve to the left    180
20       20                       Dangerous curve to the right    300
21       21                                       Double curve    270
22       22                                         Bumpy road    330
23       23                                      Slippery road    450
24       24                          Road narrows on the right    240
25       25                                          Road work   1350
26       26                                    Traffic signals    540
27       27                                        Pedestrians    210
28       28                                  Children crossing    480
29       29                                  Bicycles crossing    240
30       30                                 Beware of ice/snow    390
31       31                              Wild animals crossing    690
32       32                End of all speed and passing limits    210
33       33                                   Turn right ahead    599
34       34                                    Turn left ahead    360
35       35                                         Ahead only   1080
36       36                               Go straight or right    330
37       37                                Go straight or left    180
38       38                                         Keep right   1860
39       39                                          Keep left    270
40       40                               Roundabout mandatory    300
41       41                                  End of no passing    210
42       42  End of no passing by vehicles over 3.5 metric ...    210>
In [60]:
ix_list=list() #list of indexes to the images

for i in range(43):
    found = 0
    while found<10:
        ix=np.random.randint(0,len(y_train))
        if i==y_train[ix]:
            ix_list.append(ix)
            found+=1
plt.figure(figsize=(10,40))
for c in range(len(ix_list)):
    plt.subplot(43, 10, c+1)
    plt.imshow(X_train[ix_list[c]])
    plt.axis('off')
plt.savefig('ref/sample_input.png',bbox_inches='tight')
In [85]:
def find_rand_indexes(img_arr):
    ix_list=list() #list of indexes to the images
    for i in range(43):
        found = 0
        while found<10:
            ix=np.random.randint(0,len(y_train))
            if i==y_train[ix]:
                ix_list.append(ix)
                found+=1
    return ix_list
    
def plot_images(img_arr,ix_list):
    fig=plt.figure(figsize=(10,40))
    for c in range(len(ix_list)):
        plt.subplot(43, 10, c+1)
        img=img_arr[ix_list[c]]
        if img_arr.shape[3]==1:
            #img=np.concatenate((img,img,img),axis=2)
            img=img.reshape(32,32)
        plt.imshow(img,cmap='gray')
        plt.axis('off')
    #plt.savefig('ref/sample_input.png',bbox_inches='tight')
    
In [62]:
ix_list = find_rand_indexes(X_train)
plot_images(X_train,ix_list)

Step 2: Design and Test a Model Architecture

Design and implement a deep learning model that learns to recognize traffic signs. Train and test your model on the German Traffic Sign Dataset.

The LeNet-5 implementation shown in the classroom at the end of the CNN lesson is a solid starting point. You'll have to change the number of classes and possibly the preprocessing, but aside from that it's plug and play!

With the LeNet-5 solution from the lecture, you should expect a validation set accuracy of about 0.89. To meet specifications, the validation set accuracy will need to be at least 0.93. It is possible to get an even higher accuracy, but 0.93 is the minimum for a successful project submission.

There are various aspects to consider when thinking about this problem:

  • Neural network architecture (is the network over or underfitting?)
  • Play around preprocessing techniques (normalization, rgb to grayscale, etc)
  • Number of examples per label (some have more than others).
  • Generate fake data.

Here is an example of a published baseline model on this problem. It's not required to be familiar with the approach used in the paper but, it's good practice to try to read papers like these.

Pre-process the Data Set (normalization, grayscale, etc.)

Minimally, the image data should be normalized so that the data has mean zero and equal variance. For image data, (pixel - 128)/ 128 is a quick way to approximately normalize the data and can be used in this project.

Other pre-processing steps are optional. You can try different techniques to see if it improves performance.

Use the code cell (or multiple code cells, if necessary) to implement the first step of your project.

In [63]:
### Preprocess the data here. It is required to normalize the data. Other preprocessing steps could include 
### converting to grayscale, etc.
### Feel free to use as many code cells as needed.

#Convert all the images to gray scale
#create initial array to hold gray scale images
X_train_g=np.zeros((X_train.shape[0],X_train.shape[1],X_train.shape[2]))
X_valid_g=np.zeros((X_valid.shape[0],X_valid.shape[1],X_valid.shape[2]))
X_test_g=np.zeros((X_test.shape[0],X_test.shape[1],X_test.shape[2]))

#go through all the train images and convert them to grayscale
for i in range(len(X_train)):
    X_train_g[i]=cv2.cvtColor(X_train[i], cv2.COLOR_RGB2GRAY)
for i in range(len(X_valid)):
    X_valid_g[i]=cv2.cvtColor(X_valid[i], cv2.COLOR_RGB2GRAY)
for i in range(len(X_test)):
    X_test_g[i]=cv2.cvtColor(X_test[i], cv2.COLOR_RGB2GRAY)

#normalize/sclale all images
#(pixel - 128)/ 128 
X_train_n=(X_train_g-128)/128
X_valid_n=(X_valid_g-128)/128
X_test_n=(X_test_g-128)/128

X_train_n = np.reshape(X_train_n, (-1, 32, 32, 1))
X_valid_n = np.reshape(X_valid_n, (-1, 32, 32, 1))
X_test_n = np.reshape(X_test_n, (-1, 32, 32, 1))

print('X_train_n.shape',X_train_n.shape)
print('X_valid_n.shape',X_valid_n.shape)
X_train_n.shape (34799, 32, 32, 1)
X_valid_n.shape (4410, 32, 32, 1)

Create Syntetic Data

In [102]:
#create syntetic data

#random rotation -15 to 15 degres
X_train_r=np.zeros((X_train.shape[0],X_train.shape[1],X_train.shape[2]))

#blured images
X_train_b=np.zeros((X_train.shape[0],X_train.shape[1],X_train.shape[2]))

#zoomed images
X_train_z=np.zeros((X_train.shape[0],X_train.shape[1],X_train.shape[2]))

for i in range(len(X_train_n)):
    rows,cols =(X_train.shape[1],X_train.shape[2])
    # rotation
    deg=np.random.randint(-15,15,size=1)
    M = cv2.getRotationMatrix2D((cols/2,rows/2),deg,1)
    X_train_r[i]=cv2.warpAffine(X_train_n[i],M,(cols,rows))

    # blur
    X_train_b[i]=cv2.blur(X_train_n[i],(2,2))
    
    # zoom in
    pts1 = np.float32([[3,3],[29,3],[3,29],[29,29]])
    pts2 = np.float32([[0,0],[32,0],[0,32],[32,32]])
    M = cv2.getPerspectiveTransform(pts1,pts2)
    X_train_z[i] = cv2.warpPerspective(X_train_n[i],M,(cols,rows))
    

X_train_r = np.reshape(X_train_r, (-1, 32, 32, 1))
X_train_b = np.reshape(X_train_b, (-1, 32, 32, 1))
X_train_z = np.reshape(X_train_z, (-1, 32, 32, 1))

X_train_s=np.concatenate((X_train_n,X_train_r,X_train_b,X_train_z),axis=0)
y_train_s=np.concatenate((y_train,y_train,y_train,y_train),axis=0)
print('X_train_n.shape is ',X_train_n.shape)
print('X_train_r.shape is ',X_train_r.shape)
print('X_train_b.shape is ',X_train_b.shape)
print('X_train_z.shape is ',X_train_z.shape)
print('X_train_s.shape is ',X_train_s.shape)
X_train_n.shape is  (34799, 32, 32, 1)
X_train_r.shape is  (34799, 32, 32, 1)
X_train_b.shape is  (34799, 32, 32, 1)
X_train_z.shape is  (34799, 32, 32, 1)
X_train_s.shape is  (139196, 32, 32, 1)
In [86]:
plot_images(X_train_n,ix_list)
In [87]:
plot_images(X_train_r,ix_list)
In [88]:
plot_images(X_train_b,ix_list)
In [82]:
#
img1=np.copy(X_train_n[ix_list[0]])
img1=img1.reshape(32,32)
#img=np.concatenate((img1,img1,img1),axis=2)
#plt.imshow(img)
plt.imshow(img1)
#img1.shape
Out[82]:
<matplotlib.image.AxesImage at 0x7f4b0c3ab4e0>
In [77]:
img1=img1.reshape(32*32)
_=plt.hist(img1, bins=128)
In [101]:
img1=X_train_n[15431]
print(img1.shape)
img2=np.concatenate((img1,img1,img1),axis=2)
print(img2.shape)
(32, 32, 1)
(32, 32, 3)

Syntetic Data Visualization

In [157]:
ix=1522
img1=X_train_n[ix].reshape(32,32)
img2=X_train_r[ix].reshape(32,32)
img3=X_train_b[ix].reshape(32,32)
img4=X_train_z[ix].reshape(32,32)

title1='orig'
title2='rotated'
title3='blured'
title4='zoomed in'
f, (ax1, ax2, ax3, ax4) = plt.subplots(1, 4)
ax1.set_title(title1)
ax1.imshow(img1,cmap='gray')
ax2.set_title(title2)
ax2.imshow(img2,cmap='gray')
ax3.set_title(title3)
ax3.imshow(img3,cmap='gray')
ax4.set_title(title4)
ax4.imshow(img4,cmap='gray')
plt.savefig('ref/original_rotated_blured.png')
In [158]:
# Shuffle the training data.

X_train_s, y_train_s = shuffle(X_train_s, y_train_s)

Setup TensorFlow

The EPOCH and BATCH_SIZE values affect the training speed and model accuracy.

In [103]:
EPOCHS = 40
BATCH_SIZE = 128

Model Architecture

In [104]:
def LeNetSol(x):    
    # Arguments used for tf.truncated_normal, randomly defines variables for the weights and biases for each layer
    mu = 0
    sigma = 0.1
    
    # SOLUTION: Layer 1: Convolutional. Input = 32x32x1. Output = 28x28x6.
    conv1_W = tf.Variable(tf.truncated_normal(shape=(5, 5, 1, 6), mean = mu, stddev = sigma))
    conv1_b = tf.Variable(tf.zeros(6))
    conv1   = tf.nn.conv2d(x, conv1_W, strides=[1, 1, 1, 1], padding='VALID') + conv1_b

    # SOLUTION: Activation.
    conv1 = tf.nn.relu(conv1)

    # SOLUTION: Pooling. Input = 28x28x6. Output = 14x14x6.
    conv1 = tf.nn.max_pool(conv1, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='VALID')

    # SOLUTION: Layer 2: Convolutional. Output = 10x10x16.
    conv2_W = tf.Variable(tf.truncated_normal(shape=(5, 5, 6, 16), mean = mu, stddev = sigma))
    conv2_b = tf.Variable(tf.zeros(16))
    conv2   = tf.nn.conv2d(conv1, conv2_W, strides=[1, 1, 1, 1], padding='VALID') + conv2_b
    
    # SOLUTION: Activation.
    conv2 = tf.nn.relu(conv2)

    # SOLUTION: Pooling. Input = 10x10x16. Output = 5x5x16.
    conv2 = tf.nn.max_pool(conv2, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='VALID')

    # SOLUTION: Flatten. Input = 5x5x16. Output = 400.
    fc0   = flatten(conv2)
    
    # SOLUTION: Layer 3: Fully Connected. Input = 400. Output = 120.
    fc1_W = tf.Variable(tf.truncated_normal(shape=(400, 120), mean = mu, stddev = sigma))
    fc1_b = tf.Variable(tf.zeros(120))
    fc1   = tf.matmul(fc0, fc1_W) + fc1_b
    
    # SOLUTION: Activation.
    fc1    = tf.nn.relu(fc1)

    # SOLUTION: Layer 4: Fully Connected. Input = 120. Output = 84.
    fc2_W  = tf.Variable(tf.truncated_normal(shape=(120, 84), mean = mu, stddev = sigma))
    fc2_b  = tf.Variable(tf.zeros(84))
    fc2    = tf.matmul(fc1, fc2_W) + fc2_b
    
    # SOLUTION: Activation.
    fc2    = tf.nn.relu(fc2)

    # SOLUTION: Layer 5: Fully Connected. Input = 84. Output = 43.
    fc3_W  = tf.Variable(tf.truncated_normal(shape=(84, 43), mean = mu, stddev = sigma))
    fc3_b  = tf.Variable(tf.zeros(43))
    logits = tf.matmul(fc2, fc3_W) + fc3_b
    
    return logits
In [105]:
### Define your architecture here.
### Feel free to use as many code cells as needed.

def LeNet(x):    
    # Arguments used for tf.truncated_normal, randomly defines variables for the weights and biases for each layer
    mu = 0
    sigma = 0.1
    
    #weight = tf.Variable(tf.truncated_normal(
    #[filter_size_height, filter_size_width, color_channels, k_output]))
    #bias = tf.Variable(tf.zeros(k_output))

    #[flt_h, flt_w, clr_chnls, k_out]
    weights = {
    'wc1': tf.Variable(tf.truncated_normal([5, 5, 1, 6],mean=mu, stddev=sigma)),
    'wc2': tf.Variable(tf.truncated_normal([5, 5, 6, 16],mean=mu, stddev=sigma)),
    'wfc3': tf.Variable(tf.truncated_normal([400, 120],mean=mu, stddev=sigma)),
    'wfc4': tf.Variable(tf.truncated_normal([120, 84],mean=mu, stddev=sigma)),
    'wfc5': tf.Variable(tf.truncated_normal([84, n_classes],mean=mu, stddev=sigma))}
    #k_out
    biases = {
    'bc1': tf.Variable(tf.random_normal([6])),
    'bc2': tf.Variable(tf.random_normal([16])),
    'bfc3': tf.Variable(tf.random_normal([120])),
    'bfc4': tf.Variable(tf.random_normal([84])),
    'bfc5': tf.Variable(tf.random_normal([n_classes]))}

    # TODO: Layer 1: Convolutional. Input = 32x32x1. Output = 28x28x6.
    c1 = tf.nn.conv2d(x, weights['wc1'], strides=[1, 1, 1, 1], padding='VALID')
    c1 = tf.nn.bias_add(c1, biases['bc1'])
    
    # TODO: Activation.
    a1 = tf.nn.relu(c1)

    # TODO: Pooling. Input = 28x28x6. Output = 14x14x6.
    ksize = [1, 2, 2, 1]   #(batch_size, height, width, depth)
    strides = [1, 2, 2, 1] #(batch_size, height, width, depth)
    padding = 'VALID'
    p1 = tf.nn.max_pool(a1, ksize, strides, padding)
    
    # TODO: Layer 2: Convolutional. Output = 10x10x16.
    c2 = tf.nn.conv2d(p1, weights['wc2'], strides=[1, 1, 1, 1], padding='VALID')
    c2 = tf.nn.bias_add(c2, biases['bc2'])
    
    # TODO: Activation.
    a2 = tf.nn.relu(c2)

    # TODO: Pooling. Input = 10x10x16. Output = 5x5x16.
    p2 = tf.nn.max_pool(a2, ksize, strides, padding)

    # TODO: Flatten. Input = 5x5x16. Output = 400.
    #flt = tf.reshape(p2, [-1, weights['wfc3'].get_shape().as_list()[0]])
    flt = flatten(p2)
    
    # TODO: Layer 3: Fully Connected. Input = 400. Output = 120.
    fc3 = tf.add(tf.matmul(flt, weights['wfc3']), biases['bfc3'])

    # TODO: Activation.
    fc3 = tf.nn.relu(fc3)

    # TODO: Layer 4: Fully Connected. Input = 120. Output = 84.
    fc4 = tf.add(tf.matmul(fc3, weights['wfc4']), biases['bfc4'])
    
    # TODO: Activation.
    fc4 = tf.nn.relu(fc4)

    # TODO: Layer 5: Fully Connected. Input = 84. Output = 43.
    fc5 = tf.add(tf.matmul(fc4, weights['wfc5']), biases['bfc5'])
    
    return fc5
    #return logits
In [106]:
x = tf.placeholder(tf.float32, (None, 32, 32, 1))
y = tf.placeholder(tf.int32, (None))
one_hot_y = tf.one_hot(y, n_classes)

Train, Validate and Test the Model

A validation set can be used to assess how well the model is performing. A low accuracy on the training and validation sets imply underfitting. A high accuracy on the training set but low accuracy on the validation set implies overfitting.

In [107]:
### Train your model here.
### Calculate and report the accuracy on the training and validation set.
### Once a final model architecture is selected, 
### the accuracy on the test set should be calculated and reported as well.
### Feel free to use as many code cells as needed.
rate = 0.001

#logits = LeNet(x)
logits = LeNetSol(x)
cross_entropy = tf.nn.softmax_cross_entropy_with_logits(labels=one_hot_y, logits=logits)
loss_operation = tf.reduce_mean(cross_entropy)
optimizer = tf.train.AdamOptimizer(learning_rate = rate)
training_operation = optimizer.minimize(loss_operation)
WARNING:tensorflow:From <ipython-input-107-5a9ab11316c9>:10: softmax_cross_entropy_with_logits (from tensorflow.python.ops.nn_ops) is deprecated and will be removed in a future version.
Instructions for updating:

Future major versions of TensorFlow will allow gradients to flow
into the labels input on backprop by default.

See @{tf.nn.softmax_cross_entropy_with_logits_v2}.

In [108]:
correct_prediction = tf.equal(tf.argmax(logits, 1), tf.argmax(one_hot_y, 1))
accuracy_operation = tf.reduce_mean(tf.cast(correct_prediction, tf.float32))
predict_probability_operation = tf.nn.softmax(logits=logits)

saver = tf.train.Saver()

def evaluate(X_data, y_data):
    num_examples = len(X_data)
    total_accuracy = 0
    sess = tf.get_default_session()
    for offset in range(0, num_examples, BATCH_SIZE):
        batch_x, batch_y = X_data[offset:offset+BATCH_SIZE], y_data[offset:offset+BATCH_SIZE]
        accuracy = sess.run(accuracy_operation, feed_dict={x: batch_x, y: batch_y})
        total_accuracy += (accuracy * len(batch_x))
    return total_accuracy / num_examples

def predict(X_data):
    num_examples = len(X_data)
    sess = tf.get_default_session()
    predicted_probability = list()
    for offset in range(0, num_examples, BATCH_SIZE):
        batch_x = X_data[offset:offset+BATCH_SIZE]
        predicted_probability.extend( sess.run(predict_probability_operation, feed_dict={x: batch_x, keep_prob: 1.0}))
        
        
    return predicted_proba

Train the Model

Run the training data through the training pipeline to train the model.

Before each epoch, shuffle the training set.

After each epoch, measure the loss and accuracy of the validation set.

Save the model after training.

In [109]:
accuracy=list()
with tf.Session() as sess:
    sess.run(tf.global_variables_initializer())
    num_examples = len(X_train_s)
    
    print("Training...")
    print()
    for i in range(EPOCHS):
        X_train_s, y_train_s = shuffle(X_train_s, y_train_s)
        for offset in range(0, num_examples, BATCH_SIZE):
            end = offset + BATCH_SIZE
            batch_x, batch_y = X_train_s[offset:end], y_train_s[offset:end]
            sess.run(training_operation, feed_dict={x: batch_x, y: batch_y})
            
        #validation_accuracy = evaluate(X_validation, y_validation)
        validation_accuracy = evaluate(X_valid_n, y_valid)
        training_accuracy = evaluate(X_train_s, y_train_s)
        accuracy.append((training_accuracy,validation_accuracy))
        print("EPOCH {} ...".format(i+1))
        print("Validation Accuracy = {:.3f}".format(validation_accuracy))
        print()
        
    saver.save(sess, './lenet')
    print("Model saved")
Training...

EPOCH 1 ...
Validation Accuracy = 0.868

EPOCH 2 ...
Validation Accuracy = 0.899

EPOCH 3 ...
Validation Accuracy = 0.876

EPOCH 4 ...
Validation Accuracy = 0.915

EPOCH 5 ...
Validation Accuracy = 0.920

EPOCH 6 ...
Validation Accuracy = 0.910

EPOCH 7 ...
Validation Accuracy = 0.935

EPOCH 8 ...
Validation Accuracy = 0.935

EPOCH 9 ...
Validation Accuracy = 0.934

EPOCH 10 ...
Validation Accuracy = 0.933

EPOCH 11 ...
Validation Accuracy = 0.930

EPOCH 12 ...
Validation Accuracy = 0.947

EPOCH 13 ...
Validation Accuracy = 0.940

EPOCH 14 ...
Validation Accuracy = 0.949

EPOCH 15 ...
Validation Accuracy = 0.928

EPOCH 16 ...
Validation Accuracy = 0.954

EPOCH 17 ...
Validation Accuracy = 0.947

EPOCH 18 ...
Validation Accuracy = 0.947

EPOCH 19 ...
Validation Accuracy = 0.947

EPOCH 20 ...
Validation Accuracy = 0.951

EPOCH 21 ...
Validation Accuracy = 0.952

EPOCH 22 ...
Validation Accuracy = 0.948

EPOCH 23 ...
Validation Accuracy = 0.956

EPOCH 24 ...
Validation Accuracy = 0.946

EPOCH 25 ...
Validation Accuracy = 0.950

EPOCH 26 ...
Validation Accuracy = 0.945

EPOCH 27 ...
Validation Accuracy = 0.945

EPOCH 28 ...
Validation Accuracy = 0.955

EPOCH 29 ...
Validation Accuracy = 0.946

EPOCH 30 ...
Validation Accuracy = 0.953

EPOCH 31 ...
Validation Accuracy = 0.935

EPOCH 32 ...
Validation Accuracy = 0.952

EPOCH 33 ...
Validation Accuracy = 0.946

EPOCH 34 ...
Validation Accuracy = 0.955

EPOCH 35 ...
Validation Accuracy = 0.952

EPOCH 36 ...
Validation Accuracy = 0.943

EPOCH 37 ...
Validation Accuracy = 0.939

EPOCH 38 ...
Validation Accuracy = 0.945

EPOCH 39 ...
Validation Accuracy = 0.955

EPOCH 40 ...
Validation Accuracy = 0.951

Model saved
In [110]:
plt.plot(range(40),[ac[0] for ac in accuracy])
plt.plot(range(40),[ac[1] for ac in accuracy])
plt.ylim([.8,1])
plt.legend(['Training','Validation'])
plt.tight_layout()
plt.savefig('ref/learn_curve.png')
plt.ylabel('Accuracy')
plt.xlabel('Epoch')
plt.grid('on')
In [111]:
with tf.Session() as sess:
    saver.restore(sess, './lenet')
    training_accuracy = evaluate(X_train_s, y_train_s)
    validation_accuracy = evaluate(X_valid_n, y_valid)
    test_accuracy = evaluate(X_test_n, y_test)
    print('training_accuracy',training_accuracy)
    print('validation_accuracy',validation_accuracy)
    print('test_accuracy',test_accuracy)
INFO:tensorflow:Restoring parameters from ./lenet
training_accuracy 0.999669530734
validation_accuracy 0.951473923173
test_accuracy 0.940380047572

Step 3: Test a Model on New Images

To give yourself more insight into how your model is working, download at least five pictures of German traffic signs from the web and use your model to predict the traffic sign type.

You may find signnames.csv useful as it contains mappings from the class id (integer) to the actual sign name.

Load and Output the Images

In [112]:
os.listdir('new_img')
Out[112]:
['1.jpg', '2.jpg', '3.jpg', '4.jpg', '5.jpg']
In [113]:
### Load the images and plot them here.
### Feel free to use as many code cells as needed.
#%pwd
pics = os.listdir('new_img')
#X_new=[]
X_new=np.zeros((len(pics),X_train.shape[1],X_train.shape[2],3),dtype=np.uint8)
f, axes = plt.subplots(1, len(pics))
for fname,a,i in zip(os.listdir('new_img'),axes,range(len(pics))):
    #img = mpimg.imread(os.path.join('new_img', fname))
    img=Image.open(os.path.join('new_img', fname) )
    a.imshow(img)
    #X_new[i]=np.array(img*255,dtype='int')
    X_new[i]=np.array(img,dtype='uint8')
    #X_new.append(img)
In [114]:
print('X_test.shape',X_test.shape)
print('X_new.shape',X_new.shape)
print('X_test.dtype',X_test.dtype)
print('X_new.dtype',X_new.dtype)
#X_test[0]
#X_new[0]
X_test.shape (12630, 32, 32, 3)
X_new.shape (5, 32, 32, 3)
X_test.dtype uint8
X_new.dtype uint8

Predict the Sign Type for Each Image

In [124]:
### Run the predictions here and use the model to output the prediction for each image.
### Make sure to pre-process the images with the same pre-processing pipeline used earlier.
### Feel free to use as many code cells as needed.
y_new=[17,18,12,4,13]
X_new_g=np.zeros((len(pics),X_train.shape[1],X_train.shape[2]),dtype=np.uint8)
#gray
for i in range(len(X_new)):
    #X_new[i]=cv2.cvtColor(X_new[i], cv2.COLOR_RGB2GRAY)
    X_new_g[i]=cv2.cvtColor(X_new[i], cv2.COLOR_RGB2GRAY)

#normalize
#(pixel - 128)/ 128 
X_new_g=(X_new_g-128.0)/128.0
#print('X_new.shape',X_new_g.shape)
X_new_g=np.reshape(X_new_g, (-1, 32, 32, 1))
#sess = tf.get_default_session()
In [125]:
print('X_new_g.dtype',X_new_g.dtype)
print('X_train_s.dtype',X_train_s.dtype)
X_new_g.dtype float64
X_train_s.dtype float64
In [126]:
#
img1=np.copy(X_new_g[0])
img1=img1.reshape(32,32)
#img=np.concatenate((img1,img1,img1),axis=2)
#plt.imshow(img)
plt.imshow(img1,cmap='gray')
#img1.shape
Out[126]:
<matplotlib.image.AxesImage at 0x7f4afc553240>
In [127]:
#Predict Values
with tf.Session() as sess:
    # Load the weights and bias - No Error
    saver.restore(sess, './lenet')
    predict = sess.run(tf.argmax(logits, 1), feed_dict={x: X_new_g})
    print('predicted: ',predict)
    print('true value:',y_new)
INFO:tensorflow:Restoring parameters from ./lenet
predicted:  [17 18 12  4 13]
true value: [17, 18, 12, 4, 13]

Analyze Performance

In [128]:
### Calculate the accuracy for these 5 new images. 
### For example, if the model predicted 1 out of 5 signs correctly, it's 20% accurate on these new images.
print('Accuracy on the images from web: {:.1f}%'.format(sum(predict==y_new)/5*100))
Accuracy on the images from web: 100.0%

Output Top 5 Softmax Probabilities For Each Image Found on the Web

For each of the new images, print out the model's softmax probabilities to show the certainty of the model's predictions (limit the output to the top 5 probabilities for each image). tf.nn.top_k could prove helpful here.

The example below demonstrates how tf.nn.top_k can be used to find the top k predictions for each image.

tf.nn.top_k will return the values and indices (class ids) of the top k predictions. So if k=3, for each sign, it'll return the 3 largest probabilities (out of a possible 43) and the correspoding class ids.

Take this numpy array as an example. The values in the array represent predictions. The array contains softmax probabilities for five candidate images with six possible classes. tf.nn.top_k is used to choose the three classes with the highest probability:

# (5, 6) array
a = np.array([[ 0.24879643,  0.07032244,  0.12641572,  0.34763842,  0.07893497,
         0.12789202],
       [ 0.28086119,  0.27569815,  0.08594638,  0.0178669 ,  0.18063401,
         0.15899337],
       [ 0.26076848,  0.23664738,  0.08020603,  0.07001922,  0.1134371 ,
         0.23892179],
       [ 0.11943333,  0.29198961,  0.02605103,  0.26234032,  0.1351348 ,
         0.16505091],
       [ 0.09561176,  0.34396535,  0.0643941 ,  0.16240774,  0.24206137,
         0.09155967]])

Running it through sess.run(tf.nn.top_k(tf.constant(a), k=3)) produces:

TopKV2(values=array([[ 0.34763842,  0.24879643,  0.12789202],
       [ 0.28086119,  0.27569815,  0.18063401],
       [ 0.26076848,  0.23892179,  0.23664738],
       [ 0.29198961,  0.26234032,  0.16505091],
       [ 0.34396535,  0.24206137,  0.16240774]]), indices=array([[3, 0, 5],
       [0, 1, 4],
       [0, 5, 1],
       [1, 3, 5],
       [1, 4, 3]], dtype=int32))

Looking just at the first row we get [ 0.34763842, 0.24879643, 0.12789202], you can confirm these are the 3 largest probabilities in a. You'll also notice [3, 0, 5] are the corresponding indices.

In [129]:
#Predict Probabilites
with tf.Session() as sess:
    # Load the weights and bias - No Error
    saver.restore(sess, './lenet')
    softmax_probability = sess.run(tf.nn.top_k(tf.nn.softmax(logits=logits), k=5), feed_dict={x: X_new_g})
    print(softmax_probability)
INFO:tensorflow:Restoring parameters from ./lenet
TopKV2(values=array([[  1.00000000e+00,   4.65406658e-10,   9.84643547e-11,
          1.05274079e-12,   4.23483397e-15],
       [  1.00000000e+00,   8.50612119e-21,   5.38590546e-28,
          2.53392985e-30,   7.45917988e-37],
       [  1.00000000e+00,   7.07970651e-17,   3.67898240e-28,
          9.91775605e-30,   3.67035580e-31],
       [  1.00000000e+00,   4.17193339e-14,   1.06732633e-19,
          6.30756564e-25,   5.99929058e-30],
       [  1.00000000e+00,   0.00000000e+00,   0.00000000e+00,
          0.00000000e+00,   0.00000000e+00]], dtype=float32), indices=array([[17, 12, 33, 14, 41],
       [18, 26, 27, 15, 25],
       [12, 35, 28, 26, 41],
       [ 4,  0,  1,  5, 25],
       [13,  0,  1,  2,  3]], dtype=int32))
In [130]:
### Print out the top five softmax probabilities for the predictions on the German traffic sign images found on the web. 
### Feel free to use as many code cells as needed.

Project Writeup

Once you have completed the code implementation, document your results in a project writeup using this template as a guide. The writeup can be in a markdown or pdf file.

Note: Once you have completed all of the code implementations and successfully answered each question above, you may finalize your work by exporting the iPython Notebook as an HTML document. You can do this by using the menu above and navigating to \n", "File -> Download as -> HTML (.html). Include the finished document along with this notebook as your submission.


Step 4 (Optional): Visualize the Neural Network's State with Test Images

This Section is not required to complete but acts as an additional excersise for understaning the output of a neural network's weights. While neural networks can be a great learning device they are often referred to as a black box. We can understand what the weights of a neural network look like better by plotting their feature maps. After successfully training your neural network you can see what it's feature maps look like by plotting the output of the network's weight layers in response to a test stimuli image. From these plotted feature maps, it's possible to see what characteristics of an image the network finds interesting. For a sign, maybe the inner network feature maps react with high activation to the sign's boundary outline or to the contrast in the sign's painted symbol.

Provided for you below is the function code that allows you to get the visualization output of any tensorflow weight layer you want. The inputs to the function should be a stimuli image, one used during training or a new one you provided, and then the tensorflow variable name that represents the layer's state during the training process, for instance if you wanted to see what the LeNet lab's feature maps looked like for it's second convolutional layer you could enter conv2 as the tf_activation variable.

For an example of what feature map outputs look like, check out NVIDIA's results in their paper End-to-End Deep Learning for Self-Driving Cars in the section Visualization of internal CNN State. NVIDIA was able to show that their network's inner weights had high activations to road boundary lines by comparing feature maps from an image with a clear path to one without. Try experimenting with a similar test to show that your trained network's weights are looking for interesting features, whether it's looking at differences in feature maps from images with or without a sign, or even what feature maps look like in a trained network vs a completely untrained one on the same sign image.

Combined Image

Your output should look something like this (above)

In [ ]:
### Visualize your network's feature maps here.
### Feel free to use as many code cells as needed.

# image_input: the test image being fed into the network to produce the feature maps
# tf_activation: should be a tf variable name used during your training procedure that represents the calculated state of a specific weight layer
# activation_min/max: can be used to view the activation contrast in more detail, by default matplot sets min and max to the actual min and max values of the output
# plt_num: used to plot out multiple different weight feature map sets on the same block, just extend the plt number for each new feature map entry

def outputFeatureMap(image_input, tf_activation, activation_min=-1, activation_max=-1 ,plt_num=1):
    # Here make sure to preprocess your image_input in a way your network expects
    # with size, normalization, ect if needed
    # image_input =
    # Note: x should be the same name as your network's tensorflow data placeholder variable
    # If you get an error tf_activation is not defined it may be having trouble accessing the variable from inside a function
    activation = tf_activation.eval(session=sess,feed_dict={x : image_input})
    featuremaps = activation.shape[3]
    plt.figure(plt_num, figsize=(15,15))
    for featuremap in range(featuremaps):
        plt.subplot(6,8, featuremap+1) # sets the number of feature maps to show on each row and column
        plt.title('FeatureMap ' + str(featuremap)) # displays the feature map number
        if activation_min != -1 & activation_max != -1:
            plt.imshow(activation[0,:,:, featuremap], interpolation="nearest", vmin =activation_min, vmax=activation_max, cmap="gray")
        elif activation_max != -1:
            plt.imshow(activation[0,:,:, featuremap], interpolation="nearest", vmax=activation_max, cmap="gray")
        elif activation_min !=-1:
            plt.imshow(activation[0,:,:, featuremap], interpolation="nearest", vmin=activation_min, cmap="gray")
        else:
            plt.imshow(activation[0,:,:, featuremap], interpolation="nearest", cmap="gray")